Referring to FIG. 1, a conventional adjustable pole assembly 10 is shown having an upper pole 14 telescopically mounted within a lower pole 12. A locking unit 16 is secured to the upper end of lower pole 12. Locking unit 16 has outward extending left and right flanges 18 and 20. A lever 22 having a sharp edge 24 and a handle 26 is rotatably mounted within left and right flanges 18 and 20 and by a spring 28 between a normally biased locked position where sharp edge 24 securely engages upper pole 14 and an unlocked position upon depression of handle 26 where upper pole 14 can be adjusted. Conventional devices of this type suffer from various drawbacks. By way of example only, such conventional devices have a fully exposed sharp edge 24 that may inadvertently pinch and/or otherwise make contact with a person's finger or clothing during the unlocking and locking process thereby causing damage and/or injury. By way of further example, such conventional devices do not allow locking unit 16 to be quickly replaced at the work site. Still further, the rubber sleeve thumb grip 26 employed by such conventional devices becomes damaged by continuous contact and movement with spring 28.